Improvement in machines for cutting marble, granite



R.; R; ATCHISON. MACHINE FOR CUTTING MARBLE, GRANITE. En. No. 191,821.PatenueuJune Iz, 1877.

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lllvrTnzuA STATES PATENT GFFIGE.

ROBERT ATOHISON, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT .INMACHINES FOR cuTTlNG MARBLE, GRANITE, ac.

Specification forming part of Letters Patent No. 191,821, dated yJune12, 1877; vapplication tiled April 9, 1877.

To all whom it maycmwern:

Be it known that I, ROBERT R. ATcHIsoN, of Boston, in the county ofSuffolk and State of Massachusetts, have invented an Improvement inMachines for Cutting Marble, Granite, &c., of which the following is aspecication:

This invention relates to a machine for cutting marble, granite, stone,Snc., for vthe purposes of ornamenting or lettering the same.

Stone, marble, Svc., a-re now commonly cut by means of hand-operatedchisels, or by means of wheels. A

In this invention I employ a rapidly-rotating head, in which are chiselsattached to slide-rods, provided with rigid lateral .arms that extendwithin a cam-groove, which, as the head and chisels are rotated,rapidly-reciprocate the latter, causing their lower ends to strike thematerial with aseries of sharp, quick blows, that crumble, break, orchip out the material. A blast of air employed in connection with thesechisels blows away the waste and grit as fast as formed. The marble,stone, or other thing to be cut or engraved in accordance with thedesired design, pattern, or letters, is marked upon its surface,

. in any usual way, and moved or fed under the v chisels according tothe exigencies of thepattern. Where a number of similar articles are tobe produced, a pattern-plate is attached to the article to be cut, andit, fitted to a stud in the work support, enables the marking upon theface of the material to be dispensed with.

Figure 1 represents inside elevation a machine constructed in accordancewith this invention Fig. 2, a vertical section taken through the head;Fig. 3,a perspective view of a block of material with an attachedpattern-plate, and Fig. 4., a modified form of the tool.v

The. frame a may be of any proper 'shape and size to sustain the workingparts. The material-stone, marble, granite, wood, Svc.-

. to be cut or ornamented is placed upon a suitable work-support, b. Theslide c has bearings d, in which rotates the head e, made extern ally asa pulley, to receive a belt, f, shown in dotted lines, and extended froma suitable driven pulley, the belt passing on its way the head aboutpulleys g, to change the direction of the belt.

Aarm v and lever g,

Within the head are two slide-rods, h, having l at their lower endstools or chisels i, suitable to cut stone, marble, granite, wood, &c.,such tools being removable therefrom. Projecting laterally from each baris a rigid arm,j, provided, preferably, with a frictionroll, lc, thatenters a cam-groove, l, made in a cam-plate, m, within the box n. Anipple or nose, o, secured to the lower end of the head, assists inguiding and steadying the chisels or cutters.

If desired, spiral or other springs may be used within the heads, toassist in keeping the arms or their rollers always in contact with oneedge of the cam-groove, so that, as the groove wears, the machine willrun with less noise. The slide c is attached so as to move up and downupon the forward end of the frame. The attachment between the slide andframe is made, in this instance, by means of a dovetail gib, p, in theframe, that enters a correspondingly -shaped groove in the slide. Theslide and head are lowered to bring the tools in proper position withrelation t0 the surface of the material to be cut by means of a lever,q, connected by a link, r, or otherwise, with a treadle, s, controlledby the foot of the operator.

The spring traises the slide when it is desired to lift the tools fromcutting position.

The tools may be adjusted to accord with the thickness of the materialby means of a screw, u, that enters the arm e, extended through a slotin the frame and into an opening in the slide. This screw turns in, butdoes not move longitudinally with reference to, the slide, and, enteringa tapped hole in the arm e, it, when rotated, will move the slideandhead vertically with relation to the thereby causing the tools, whendepressed by the lever and treadle, to descend more or less. As the headis rotated the arms j, entering the cam-shaped groove, are acted upon toraise and lower the tools quickly, so that they strike the materialrapidly, and cut or remove it. The tools, having a combinedreciprocating and rotating motion, strike a blow especially suited tobreak away, crumble, or cut out stone, marble, &c., and material of akindred nature. By changing the position of the slide the cut into thesurface may be continued to the desired depth.

The tool best adapted to marble has a semicrcular end, as, for instance,as shown in Fig. I. For granite a tool with a point, as shown in Fig. 4,has been found best. For wood, &c., the tool will be of proper shape toremove portions of the surface of the material with a clean,well-defined cut.

Where a number of articles of like pattern are to be cut, apatternplate, w, cut out to correspond with the pattern to be cut, (seedotted lines,) is attached to the under o1' back face of thtl materialto be cut, as, for instance, a', and the pattern-plate titted to aguide, b', in the work-support b, may be moved according to the pattern,to cause the tools to cut away the face of the material in accordancewith such pattern.

This mechanism cuts stone, marble, and granite much more rapidly andbetter than usual with a hand chisel or tool. It has also been foundadmirable for cutting.,r out the surface of gilt and other enameledpicture-frames, and is specially adapted for carving wood.

The rigid arms are short and stift', and lift the slide-rods positively.They may be removed, if desired to renew them. The extent of the motionof' the slide bars may be governed by changing the plate containing thecam-groove.

Instead of a blast to remove chippings, Sto., an exhaust may be used todraw such refuse away.

I claim- 1. The combination, with the rotating head and cani-groove, ofchisels or tools and sliderods, provided with rigid arms, extended intothe cam-groove, to operate substantially as described.

2. The rotating head and tools and mechansm to reciprocate the tools, incombination with a vertically-movable slide and mechanism to lower thehead into working position, substantially as described.

3. The head-carrying slide and the rotary head c and its tools fi fi,adapted to be reciprocated, as described, in combination with the leverto move the slide and an adjusting device, u, to change the position ofthe slide with reference to the end of the arm, to govern the descent ofthe tools and head, according to the thickness of the material and thedepth of the cut required therein.

4. The rotating head and reciprocating tools carried thereon, incombination with a support for the material and mechanism to raise andlower the head, substantially as described.

5. The rotating head and reciprocating tools, in combination with a pipeto conduct air to discharge the cuttings from the'face of the material,substantially as described.

The rotating head and reciprocating tools, in combination with asupporting-surface and a guide and pattern-plate, to operatesubstantially as described.

In testimony whereof I have signed my name to this specication in thepresence ot' two subscribing witnesses.

ROBERT RALSTON ATCHISON.

Witnesses:

G. W. GREGoBY, W. J. PRATT.

